The compartment liner conception of use with liquid bulk carrying vessels as expressed in the prior art is well known. Compartment liners and buffer zones have been incorporated into modern tanker vessels in an effort to avert the tremendous damage that floating oil spills cause. However, the bulk liquid carrying vessel industry has come under increasing pressure to create safer methods to transport bulk liquids across open seas.
Compartment liners and buffer zones are vulnerable to puncture and tear in the event of grounding or collision wherein steel is forced inward by external pressure. Double hulled vessels have been suggested as a way to avert these inboard steel hazards in the event of grounding or collision. However, the ten to twelve foot void between hulls is wasted space and renders the double hull concept inefficient. Even double hulled vessels are still vulnerable to spills.
Bulk liquid carrying tankers stand thirty to forty feet below the water's surface when loaded. Steel being forced in ward from a severe grounding would likely puncture or fracture the inner hull as there is nothing to absorb the shock of grounding of collision except empty space.
As previously stated, the compartment liner concept is well known in the oil tanker industry. However, the liners in most cases are composed of epoxy based filament reinforced coatings sprayed directly onto the walls of the vessel.
These spray-on coating are intended primarily to guard against leakage of oil or other pollutants through cracks or fractures in the welds of the vessel's steel plating, but would do little in preventing spillage in the event of grounding or collision.
The releasable fixed bag type liner of McLaughlin U.S. Pat. No. 3,844,239 which attached to the wall of the compartment would absorb the full impact or grounding or collision without the benefits of the present invention.
There is not protection provided against ruptures and tearing by steel beams in the event of a collision. The vessel's plating is forced inward in the event of a collision as no counterforce or cushioning effect is offered in the prior art. In the present invention the cargo is contained in the hermetically sealed vinyl bag or liner of a predetermined thickness and spaced apart from the hull of the tanker.
The vinyl liner is fastened in the compartment with enough play in the bag to allow unrestricted movement of the liquid cargo such as oil. The cargo contained within the liner is supported in most part by the vessel's superstructure by shock absorbing coil springs and heavy steel cables encased in thick rubber matting. This arrangement relieves much of the stress from the vessel's steel plating and welded seams.